It's the difference between are and were. Age is an indication that you existed at some point in the past. It's a compacted record of reality. You cant change t

It's the difference between are and were. Age is an indication that you existed at some point in the past. It's a compacted record of reality. You cant change that arbitrarily even if you "feel younger". Changing gender simply is a desire to change what you are currently. The whole notion of transitioning is to change from what you were to something that you feel more comfortable being.